The sum of two positive whole numbers is 10 and their product is 72. If x is one number then, which of these equations will give the two numbers?
Answers
Ok, so we already have solutions for how to use algebra to arrive at the answer. Using the formula for roots to a quadratic equation.
I will tell you 2 ways to arrive at the answer with using a pen and paper. I call them the fast way and the faster way. Alternatively, the easy way and the easier way.
Fast or Easy Way:
Sum is 31 (Mental note - I am looking for an odd and an even number for their sum to be an odd number)
Product is 150 (Mental note - the product should give me a 0 at the end)
Since I need an odd number, lets run through odd numbers and what they would need to be multiplied with to get 150.
1, 3, 5 eliminated as they are too small (5*30 is 150 but 5+30 is 35)
Eliminate 7, 9, 11, 13 as they dont give 150 with any multiplication.
Eliminate 15 as 150= 15*10, 15+10 = 25.
Eliminate all upto 25 because they wont give 0 at the end unless they are multiplied with 10.
Finally 25*6=150; 25+6 = 31.
Looks a little complicated. But a little common sense, elimination becomes very fast.
Faster or easier Method:
My 2 numbers multiplied should give 150. Lets break it down.
150= 50*3 (Mental note: 50+3 =53)
=25*2*3 (Mental note: 25+(2*3)=31)
Done!
Follow me dear for your future doubts ❤️❤️❤️
At times, you dont always have to go all mathematical, use algebra and get to the solution. Its easier and better for us to use our mind and logic and find a solution.
Cheers!
Answer:
First number= x
Second number= y
⇒ x+y= 10
⇒ xy= 72
Hope it helps.
Please mark my answer as BRAINLIEST.